Radio frequency radiation shield device

ABSTRACT

A radio frequency radiation shield device may comprise a receiver for detecting a near field radio frequency signal at target frequencies. The shield device may further comprise a signal processor that samples signal characteristics of a detected signal and determines a nullifying signal in response to detecting a signal characteristic of the detected signal meeting a trigger threshold. The nullifying signal may comprise a modulated version of the detected signal. The shield device may further comprise a signaler for generating the nullifying signal. The shield device may further comprise a transmitter for transmitting the nullifying signal at target signals.

BACKGROUND

The present disclosure relates to a radio frequency radiation shielddevice, and more specifically, to an active radio frequency radiationshield device for transmitting nullifying signals.

Radio waves are used in a number of security access devices, such as,remote keyless entry (RKE) vehicle devices and radio frequencyidentification (RFID) access cards, and such devices may need protectionagainst incoming radio waves utilized in amplification, relay, or otherforms of attacks used to operate the target equipment in ways it was notintended.

Taking the example of RKE, tens of millions of vehicles worldwide usethis technology. A key fob is provided with a radio frequency antenna.When the driver touches the door handle for example, the car detectsthis and sends a low frequency message using near field communicationsto the key fob, which is usually on the driver. The key fob receivesthis near field communication and sends back a higher frequency messageto the vehicle authorizing the unlocking of the vehicle doors. The sameprocess is used for remote keyless start. When the driver sits in thevehicle seat and presses the start button, the car uses a near fieldantenna around the driver's seat to again send a near field message tothe key fob, which in turn responds with a higher frequency messageauthorizing the vehicle to start the engine.

The security failing in this technology is that near fieldcommunications, which are radio frequency communications that operate inthe near field utilizing transmission signals of very weak power tocommunicate, can be relayed or amplified. This invalidates the designassumption that near filed communications only work in close proximity.When a relay attack is used, a small near field receiver is used by anattacker when they approach the vehicle, their partner has the other endof the relay tool and points it to where the attackers believe the keyfob is located inside a house. The relay receives the near fieldmessage, relays it to the other end of the tool, which then sends themessage out with much higher power. The key fob receives the message andbelieves it must be near the vehicle so it sends back a message toauthorize the action.

An amplification attack is similar, but simpler. A near field antenna ona wand is used by a first attacker and it is connected via a cable tothe other end which is used by a second attacker with an amplifier. Whenthe wand receives the message, the amplifier re-transmits it with muchhigher power. The same process then occurs where the key fob receivesthe message and authorizes the action.

A Faraday cage is a known form of protection in the form of an enclosureused to block electromagnetic fields. A Faraday cage is an enclosureformed by a continuous covering of conductive material or mesh. Anexternal electrical field causes the electric charges within the cage'sconducting material to be distributed such that they attenuate thefield's effect in the cage's interior. This is used to protect sensitiveelectronic equipment from external radio frequency interference.

Faraday cages or Faraday bags that provide Faraday cage functions areexpensive and the more they are used the less effective they becomebecause of wear and tear to the seals. Also, discipline is required toalways put a key fob or other device inside the Faraday bag.Furthermore, radio frequencies used in RKE or RFID are very hard toblock as they are low frequency waves.

SUMMARY

According to an aspect of the present disclosure there is provided aradio frequency radiation shield device, the device comprising: areceiver for detecting a near field radio frequency signal at targetfrequencies; a signal processor for, responsive to detecting a signalcharacteristic of a detected signal meeting a trigger threshold:sampling signal characteristics of the detected signal; and determininga nullifying signal that results in interference with the detectedsignal to render the detected signal ineffective, the nullifying signalcomprising a modulated version of the detected signal; a signalgenerator for generating the nullifying signal; and a transmitter fortransmitting the nullifying signal at the target frequencies.

This has the advantage of responding to a detected incoming signal bytransmitting a nullifying signal to protect electronic devices withinthe transmission field of the shield device. The protection may be bypreventing the electronic device from receiving a valid incoming signalor by preventing an incoming signal leaking from the electronic devicefrom being received by other parties.

The signal processor may repeat the sampling and transmitting of adetermined nullifying signal at time intervals to provide the nullifyingsignal in response to a presence and form of the detected signal. Thisfeature may cause the nullifying signal to be varied, which may nullifyvarying incoming signals.

In one embodiment, the signal processor for determining a nullifyingsignal may determine that there is a signal providing destructiveinterference with the detected signal to cancel or dampen the detectedsignal. This may result in no or a minimal resultant signal that cannotbe read. In another embodiment, the signal processor for determining anullifying signal may determine that there is a signal providingpositive interference to interfere with the detected signal and renderit ineffective. This may result in a resultant signal that has itsmessage rendered invalid or unable to be read. In a further embodiment,the signal processor for determining a nullifying signal may determine adifferent form of interference for different time portions of thedetected signal. This may be used, for example, to cancel a messagepreamble and invalidate a message checksum.

The signal processor may include a signal deviationer for adding adeliberate deviation of random or pseudo random nature to the nullifyingsignal. This has the advantage of preventing an incoming signal fromadapting to the nullifying signal and thereby rendering it ineffective.

A passive mode of the signal processor may be enabled to monitorreceived signals and an active mode of the signal processor may beenabled when signal characteristics of a detected signal on meet thetrigger threshold. This has the advantage of enabling a low-power,standby passive mode when no incoming signal is detected.

The receiver and the transmitter may be arranged to provide one or moreaxis of sufficient signal sensitively suitable for a current applicationof the shield device. The receiver and transmitter may provide suitablereceive and transmit gain at target frequencies for a currentapplication of the shield device.

In one application, the shield device may protect a protected electronicdevice wherein the detected signal is an unwanted incoming signal to theprotected electronic device positioned within a transmission field ofthe shield device. In another application, the shield device may protecta protected electronic device from leaking the detected signal whereinthe detected signal is a leaking signal from the protected electronicdevice positioned within a transmission field of the shield device. Theshield device may provide both forms of protection (e.g., the stoppingof a leaking detected signal and the stopping of an interfering,nefarious signal) simultaneously for protected electronic devices withinits field range.

In one embodiment, the shield device may be provided as a portabledevice with a portable power supply or connectable to a power source. Inanother embodiment, the shield device may be provided in an integratedcircuit for protecting integrated electronic components of a device.

In one embodiment, the shield device may protect remote keyless entryfobs with target frequencies in the range of 125 KHz or 134.5 KHz fromrelay attacks.

According to another aspect of the present disclosure there is provideda signal processing method for providing a radio frequency radiationshield, comprising: detecting a near field radio frequency signal attarget frequencies; responsive to detecting a signal characteristic of adetected signal meeting a trigger threshold, sampling signalcharacteristics of the detected signal; determining a nullifying signalthat results in interference with the detected signal to render thedetected signal ineffective, the nullifying signal comprising amodulated version of the detected signal; generating the nullifyingsignal; and controlling the transmitting of the nullifying signal usinga transmitter.

The method may include repeating the sampling and transmitting of adetermined nullifying signal at time intervals to provide the nullifyingsignal in response to a presence and form of the detected signal.

The determining a nullifying signal may comprise: determining that thereis a signal providing destructive interference with the detected signalto cancel or dampen the detected signal; determining that there is asignal providing positive interference to interfere with the detectedsignal and render it ineffective; and/or determining that there is adifferent form of interference for different time portions of thedetected signal.

The method may include: disabling or ignoring the receiver once adetected signal is sampled; enabling the transmitter to transmit thenullifying signal; disabling the transmitter after a transmittinginterval; enabling or reading the receiver to resample the detectedsignal; and repeating the process as long as a detected signal isreceived.

The method may include adding a deliberate deviation of random or pseudorandom nature to the nullifying signal.

The method may provide a passive mode of a signal processor to monitorreceived signals and an active mode of the signal processor when signalcharacteristics of a detected signal meet the trigger threshold.

According to a further aspect of the present disclosure there isprovided a signal processing system for providing a radio frequencyradiation shield, comprising: a signal receiver for receiving a detectednear field radio frequency signal at target frequencies; a signalsampler for, responsive to detecting a signal characteristic of adetected signal meeting a trigger threshold, sampling signalcharacteristics of the detected signal; a signal nullifier fordetermining a nullifying signal that results in interference with thedetected signal to render the detected signal ineffective, thenullifying signal comprising a modulated version of the detected signal;and a signal controller for controlling the transmitting of thenullifying signal.

According to a further aspect of the present disclosure there isprovided a radio frequency radiation shield device, the devicecomprising: a receiver for detecting a near field radio frequency signalat target frequencies; a signal processor for, responsive to detecting asignal characteristic of a detected signal meeting a trigger threshold:sampling signal characteristics of the detected signal; and determininga nullifying signal that results in destructive interference with thedetected signal to render at least part of the detected signalineffective; a signal generator for generating the nullifying signal;and a transmitter for transmitting the nullifying signal at the targetfrequencies.

According to a further aspect of the present disclosure there isprovided a signal processing method for providing a radio frequencyradiation shield, comprising: detecting a near field radio frequencysignal from at target frequencies; responsive to detecting a signalcharacteristic of a detected signal meeting a trigger threshold,sampling signal characteristics of the detected signal; determining anullifying signal that results in destructive interference with thedetected signal to render at least part of the detected signalineffective; generating the nullifying signal; and controlling thetransmitting of the nullifying signal using a transmitter.

BRIEF DESCRIPTION OF THE DRAWINGS

The subject matter regarded as the disclosure is particularly pointedout and distinctly claimed in the concluding portion of thespecification. The disclosure, both as to organization and method ofoperation, together with objects, features, and advantages thereof, maybest be understood by reference to the following detailed descriptionwhen read with the accompanying drawings.

The drawings included in the present disclosure are incorporated into,and form part of, the specification. They illustrate embodiments of thepresent disclosure and, along with the description, serve to explain theprinciples of the disclosure. The drawings are only illustrative ofcertain embodiments and do not limit the disclosure.

FIG. 1 illustrates a block diagram of an example embodiment of a shielddevice, in accordance with the present disclosure.

FIG. 2 illustrates a flow diagram of an example embodiment of a method,in accordance with the present disclosure.

FIG. 3 illustrates a schematic diagram of a waveform illustrating theresult of the present disclosure.

FIGS. 4A, 4B, and 4C illustrate various schematic diagrams of portionsof the waveform of FIG. 3.

FIG. 5 illustrates a schematic diagram of an example embodiment of asignal sampling aspect of the method and system, in accordance with thepresent disclosure.

FIGS. 6A and 6B illustrate various schematic diagrams of two scenariosof use of a shield device, in accordance with the present disclosure.

It will be appreciated that for simplicity and clarity of illustration,elements shown in the figures have not necessarily been drawn to scale.For example, the dimensions of some of the elements may be exaggeratedrelative to other elements for clarity. Further, where consideredappropriate, reference numbers may be repeated among the figures toindicate corresponding or analogous features.

While the embodiments described herein are amenable to variousmodifications and alternative forms, specifics thereof have been shownby way of example in the drawings and will be described in detail. Itshould be understood, however, that the particular embodiments describedare not to be taken in a limiting sense. On the contrary, the intentionis to cover all modifications, equivalents, and alternatives fallingwithin the spirit and scope of the disclosure.

DETAILED DESCRIPTION

A radio frequency radiation shield device is provided and a signalprocessing method for providing a radio frequency radiation shield. Theshield device includes a receiver for detecting a near field radiofrequency signal including one or more receiving antennas for targetfrequencies and a transmitter including a transmitting antenna at thetarget frequencies for transmitting a nullifying signal. The shielddevice includes a signal processor for, responsive to detecting a signalcharacteristic of a detected signal on a receiving antenna meeting atrigger threshold: sampling signal characteristics of the detectedsignal; and determining a nullifying signal that results in interferencewith the detected signal to nullify the detected signal, the nullifyingsignal comprising a modulated version of the detected signal, and asignal generator for generating the nullifying signal.

A radio frequency radiation shield device is described for providing anullifying radio frequency signal to at least partially cancel out orotherwise interfere with a detected incoming radio frequency signal. Theshield device may be used in a range of situations. In some situations,the shield device may be used to protect another device in the vicinityof the shield device, such as a remote keyless entry (RKE) vehicledevice, a radio frequency identification (RFID) access card or sensitiveequipment, by preventing an incoming signal from reaching the protecteddevice. In other situations, the shield device may protect againstsignal leakage from a signal protected area or device.

Referring to FIG. 1, illustrated is an example embodiment of a radiofrequency shield device 100, in accordance with the present disclosure.

The radio frequency radiation shield device 100 includes one or morereceiving antennas in a receiving antenna arrangement 111 for detectinga near field radio frequency signal at target frequencies and one ormore transmitting antennas in a transmitting antenna arrangement 121 fortransmitting a dampening or cancelling radio frequency signal inresponse to detecting an incoming signal on the receiving antennaarrangement 111.

The antennas may be suitable for a signal frequency range for a givenapplication of the shield device 100.

For each of the receiving and transmitting antenna arrangements 111, 121one or more antenna may be used; alternatively, a combined receiving andtransmitting antenna may be used proving both the receiving andtransmitting antenna arrangements 111, 121 in a single antenna.

In some embodiments, two antennas may be provided at 90 degrees toprovide a greater coverage of the receiving or transmitting area. Nearfield antenna are highly directional as they work on the flow ofmagnetic flux. The signal from a near field antenna is strongest infront and behind and weak from the sides. To improve the signalcoverage, two antennas may be provided at 90 degrees (e.g., orthogonal,perpendicular) to each other. In other embodiments, more than tworeceiving or transmitting antennas may be used for greater coverage.Many known arrangements of antennas may be utilized.

The receiving and transmitting antennas in the antenna arrangements 111,121 may be tuned or unturned and may be, as examples, near field coil,ceramic chip, printed circuit or any other type of suitable antennas. Inone embodiment, ferrite core coil antennas are used due to sensitivityof the chosen frequency and very low cost to produce.

The receiving antenna arrangement 111 may intercept radio waves andconvert these to an electrical signal and may be part of a receiver 110at the shield device 100 that extracts information using electronicfilers to separate the radio frequency signal from other signals and mayinclude an amplifier 112 for providing required amplification of thereceived signals and a demodulator 113 for detecting an incoming signal.

The transmitting antenna arrangement 121 may transmit a modulated radiosignal and may be part of a transmitter 120 at the shield device 100.The transmitter 120 may include or be connected to a signal generator123 for generating a modulated signal for transmission and an amplifier122 for generating and driving the transmitted signals.

The antenna arrangements 111, 121 may be driven by many different typesof driver or amplifier including a resonant circuit or analoguedriver/amplifier.

A signal processor 130 is provided in the shield device 100 withprocessing capability for sampling a detected signal and determining anullifying signal required to dampen or cancel out the detected signaland to instruct the signal generator 123 to generate the nullifyingsignal.

The nullifying signal may be any signal that destructively and/orotherwise interferes with the detected signal that results in thedetected signal being modified, cancelled or other way rendered uselessfor its purpose, such as an attack signal or as a leaked signal. Thenullifying signal may be a dampening signal or a cancellation signal orother type of interference signal. The term positive interference isused for a signal that interferes with the detected signal in such amanner as to render it useless.

Different forms of positive or negative interference may be used atdifferent stages or time domains of the detected signal in order to makethe detected signal useless. This may cancel out the detected signal inthe near field and/or target particular parts of a message in thedetected incoming signal.

In the example case of protection against an attack, the nullifyingsignal may be an identical signal to the detected signal and may betransmitted at out of phase, which will destructively interfere and, atleast partially, cancel the detected signal. In another example, adifferent nullifying signal that results in a frequency shift of thedetected signal through positive interference will have the same resultin that the detected signal is rendered ineffective and the protecteddevice does not receive the detected signal. In other examples, acombination of destructive and positive interference may be used. Thiscombination may be used at different stages of a message in an incomingdetected signal, for example, to cancel out a message pre-amble and thenpositively interfere with a message checksum or cyclic redundancy check.

As the detected signal is a demodulated version of the incoming sourcesignal, the nullifying signal may be a modulated version of themodulations of the detected signal, either provided out of phase orotherwise adapted to interfere with the incoming signal. The processdemodulates the incoming signal to see if it is actually a message; ifit is, then a nullifying message may be created which is modulated toform the nullifying signal.

The signal processor 130 may include a processor 131, such as amicroprocessor, a hardware module, or a circuit for executing thefunctions of the described components which may be firmware or softwareunits executing on the processor 131. Memory 132 may be configured toprovide computer instructions 133, such as firmware, to the at least oneprocessor 131 to carry out the functionality of the components.

The signal processor 130 may include a signal receiver 140 for receivinga detected signal from the receiver 110. The signal processor 130 mayinclude a signal trigger 141 and an active/passive mode controller 134for switching the signal processor 130 between active and passivestates. In a passive state, the signal processor 130 may receivedetected signals and may use the signal trigger 141 to measure thedetected signals against a threshold of one or more signalcharacteristics to determine if an active state should be triggered. Theactive/passive mode controller 134 may activate an active state if adetected signal has one or more characteristics that rise above thethreshold. An active state may sample the detected signal and carry outfurther processing to instruct the transmission of a respondingdampening signal. The active/passive mode controller 134 may deactivatethe active mode when a trigger signal is no longer being received andmay revert to a passive mode of operation of the signal processor 130.

The signal processor 130 may include a signal sampler 136 for sampling areceived detected signal when in the active mode and a signal nullifier138 for determining a nullifying signal to nullify the detected signalas described further below.

The detected signal may be sampled to determine basic signalcharacteristics. Signal processing may be used to generate and transmitthe nullifying signal a fraction of a wavelength later. The signalsampling may use multiple samples to determine signal characteristicsand may therefore involve a signal phase lag as filters may require anumber of samples to produce the nullifying signal as an output signal.

The signal processor 130 may include a signal controller 142 (e.g.,signal output component) for outputting the nullifying signal.

The signal processor 130 may include a sampling intervaler 137 fordetermining intervals between the signal sampling and transmitting thenullifying signal. An antenna controller 135 may be provided forswitching between receiving a detected signal from the receiving antennaarrangement 111 and transmitting a nullifying signal from thetransmitting antenna arrangement 121. The antenna controller 135 may bepart of the signal processor 130 or may be a separate component.

The signal processor 130 may include a signal deviationer 139 for addinga deliberate deviation signal of a random nature to the dampening signalto prevent an attacker from adapting the incoming signal that is beingdetected.

The shield device 100 may take various forms and sizes and may be sosmall it fits inside an integrated circuit, say a hardware securitymodule (HSM) or trusted platform module (TPM) or may be larger toprotect an area or room from signal leakage as described further below.

Referring to FIG. 2, illustrated is a flow diagram showing an exampleembodiment of the method 200 as carried out at the signal processor 130of the shield device 100, in accordance with the present disclosure.

The method 200 begins at operation 201, where a processor receives andmonitors signal characteristics of a detected signal at the receivingantenna arrangement 111 of the shield device 100 when the device is in apassive mode. The method 200 proceeds to operation 202, where a signalcharacteristic is detected. The method 200 proceeds to decision block203 where it is determined if the detected signal characteristic meets apredefined trigger threshold. If the detected signal characteristic doesnot meet the trigger threshold at decision block 203, the method 200begins again, reverting back to operation 201 where the processorcontinues monitoring the detected signal to detect a further change inthe characteristic.

The signal characteristic may include one or more of a change or levelof: frequency, modulation timing, amplitude and phase. For example, asignal characteristic may be a rise in signal amplitude. Sophisticatedsignal characteristics may be monitored and detected if the aim isdetection of a known form of incoming signal.

If, at decision block 203, the detected signal characteristic meets thetrigger threshold, the method 200 proceeds to operation 204 where anactive mode of the shield device is activated, in which the detectedsignal is sampled and nullified by generating a nullifying transmittedsignal.

The method 200 proceeds to operation 205, where while the device is inthe active mode, samples the incoming signal. The method 200 proceeds todecision block 206 where it is determined if the signal is stillpresent. If the signal is no longer present, at decision block 206, themethod 200 proceeds to operation 207, where the active mode of theshield device is deactivated and the method 200 begins again atoperation 201 and continues to monitor detected signals in the passivemode.

If the detected signal is still present at decision block 206, themethod 200 proceeds to operation 208, where the processor samples thecharacteristics of the incoming signal, the processor obtaining a stablelock is on the incoming signal based on the samples. The sampledcharacteristics may include the frequency, modulation, timing, amplitudeand phase of the incoming signal. The method 200 proceeds to operation209 where a required nullifying signal for the sampled signal isdetermined.

The nullifying signal may be determined at operation 209 as a signalthat destructively or positively interferes with the sampled signal thatresults in the detected signal being modified, cancelled or other wayrendered useless. For example, the nullifying signal may be an out ofphase, modulated version of the sample signal in order to cancel theincoming signal.

The method 200 proceeds to operation 210, where a receiving antennaarrangement is disabled and the transmitting antenna arrangement isactivated. The method 200 proceeds to operation 211, where thetransmitting antenna arrangement transmits the nullifying signal for agiven time interval. The nullifying signal may modulate the output ofthe transmitting antenna arrangement to re-enforce the antenna's naturalresonance.

The time interval of sampling and transmitting is dependent on theimplementation of the shield device and may be in the order ofnanoseconds to many seconds with the aim of preventing the receiving ofan intact message in a detected incoming signal.

The method 200 proceeds to operation 212, where the transmitting antennaarrangement is disabled and the receiving antenna arrangement isreactivated. In some embodiments, the method 200 may loop to operation205 and continue sampling an incoming signal. The method 200 maycontinue to loop in order to nullify the sampled detected signal untilthe signal is no longer present, after the signal is no longer presentthe method 200 may end. In some embodiments, the method 200 may endafter operation 212.

In an alternative embodiment, a receiving antenna may continue toreceive a detected signal and may ignore or continue sampling thereceived signal whilst transmitting a nullifying signal.

Referring to FIG. 3, illustrated is a schematic diagram showing awaveform graph 300 of a signal amplitude 310 against a time 320 of adetected source signal 301, a nullifying signal 302, and a resultantsignal 303. The amplitude of the resultant signal 303 is reduced on thewaveform graph 300 for illustration. The graph 300 shows the overallprocess of dampening the detected source signal 301 with the nullifyingsignal 302 in the form of a dampening signal to result in a cancellationof the source signal 301. This illustrates the advantages of the presentdisclosure by empirically demonstrating how a nullifying signal 302 canbe used to protect a device.

Referring to FIGS. 4A, 4B and 4C, illustrated are schematic diagramsshowing graph portions 400, 410, 430 of the waveform graph 300 of FIG.3.

FIG. 4A shows the graph portion 400 of a detected source signal 401 withan illustrated resultant signal 403 with a lower illustrated amplitudefor illustration purposes so that both the detected source signal 401and a resultant signal 403 show on a single graph.

FIG. 4B shows the graph portion 410 of a detected source signal 411 andat time point 421 along the horizontal axis when a dampening signal 412is applied, and at time point 422 when the dampening signal 412 stops inorder to re-sample the detected signal. At a time point 423, thedampening signal 412 starts again, then stops again at a time point 424.The resultant signal 413 settles into a resultant null signal.

FIG. 4C shows a graph portion 430 of a settled pattern of a detectedsource signal 431 and a dampening signal 432 cancelling out the detectedsource signal 431 with an almost flat resultant signal 433.

A source signal is modulated or varied over a base signal in order tosend data. The modulation may be Frequency Modulation, in which thefrequency is modulated, or Amplitude Modulation in which the amplitudeis modulated. To receive the source data, the signal is demodulated. InFIGS. 3 and 4A-4C, the source signal is amplitude modulated. So, thesource signal is either on (e.g., sine wave) or off (e.g., flat) torepresent two binary states of 1 and 0. Putting the modulations togetherresults in a message. By monitoring signal characteristics by looking atsource signal amplitude, frequency and phase, it can be determined howthe source signal is communicating data and a nullifying signal may begenerated to cancel out that message.

There may also be a small deliberate deviation of random nature added tothe nullifying signal. The deliberate deviation helps prevent anattacker from adapting to the nullifying signal.

The additional deliberate deviation modulation may be used because inthe real world it is not possible to remove the source signal 100%;therefore, adding an additional small modulation confuses the receivingdevice as to what the signal really is.

Referring to FIG. 5, illustrated is a schematic diagram 500 of anexample embodiment of a signal sampling aspect of the described methodand system, in accordance with embodiments of the present disclosure.

The incoming signal 510 has signal characteristics in the form of itsfrequency, phase, and amplitude shown. The detected incoming signal mayinclude amplitude modulation to include a message by a sequence ofeither on (e.g., sine wave) or off (e.g., flat) to represent a sequenceof bits 1, 0 of the message. The incoming signal may be demodulated intothe message to get message bits for nullifying; or alternatively,broader signal characteristics such as frequency and amplitude may beused for determining and generating the nullifying signal depending onthe use case.

The incoming signal 510 is sampled to determine that it is the detectedsignal with the signal characteristics. Signal processing needs x numberof samples 520 sent to an array of x elements 530 to determine 540 ifthe signal matches the signal characteristics. The signal processormight take until [n+p] as in the pth sample in the bucket to determinethat the signal matches the signal characteristics.

Once it is determined that the incoming signal matches the signalcharacteristics and identifies the signal as the signal to be nullified,then a transmission gate and modulator 550 may latch the output on andthe negative of [n] or (0−[n]) may then be transmitted 560.

The determination 540 has a phase lag but, once triggered, may transmitnear-perfectly in sync with the incoming signal. The incoming signalwould be sampled to determine basic signal characteristics (such as thefrequency, phase, amplitude) and the transmission of the nullifyingsignal may happen a fraction of a wavelength later.

Referring to FIG. 6A, illustrated is a schematic diagram 600 showing afirst scenario of an application of a described shield device 601. Aprotected electronic device 602 may be placed near the shield device601. An incoming signal 611 detected by the shield device 601 may benullified by a transmitted nullifying signal 612 from the shield device601. This results in the incoming signal 611 being rendered ineffectiveat the protected electronic device 602. Any electronic device within atransmitting area 605 of the shield device 601 is protected from theincoming signal 611.

One described embodiment of the first scenario of FIG. 6A is the shielddevice 601 provided as a remote keyless entry (RKE) shield device. TheRKE shield device may be a small, portable device powered by a USB orbattery and designed to be placed near to where a user keeps their keys.

In the event of an RKE style attack, the RKE shield device senses thenear field message and immediately transmits a nullifying field so thekey fob never receives a valid message. In one embodiment, thenullifying signal is a cancellation signal so that no signal is receivedat the key fob. Once the RKE attack ends, the RKE shield device goesback into passive mode.

In the example embodiment of a RKE key fob, the detected source signalis the RKE attack signal, the nullifying signal 612 is the transmittedsignal produced by the RKE shield device and the resultant signal iswhat the key fob sees.

The RKE shield device may include tuned antennas tuned to radiofrequencies in the range from 120 KHz to 140 KHz. A more specific rangefor the RKE shield example may be 125 KHz or 134.5 KHz, depending on theregion.

In the example implementation for RKE shielding purposes, a messagetransmitted from a vehicle to the key fob is typically less than 100 ms.As such, any transmission period that covers more than a messagepre-amble is suitable as a time interval.

In an embodiment, the RKE shield device may transmit a 90 degrees out ofphase signal and modulates the signal to ensure that no matter howsensitive the key fob is, the attacker's message is never received.

The RKE shield device senses an attack and protects keys within range(e.g., within the transmitting area 605). A user does not have to doanything apart from place their keys nearby. Multiple key fobs may beprotected by a single RKE shield device, if they are placed withinrange. The shield device provides a protective a radio force field anddoes not require any change to the existing design of vehicles alreadyin production and sold.

The RKE shield device is independent of a vehicle make or model and canused on existing vehicles vulnerable to remote keyless entry attacks. Itdetects the simple presence of RKE style attacks and protects the keyfob irrespective of modulation specifics.

In another described embodiment of the first scenario of FIG. 6A, theshield device 601 may be used to protect RFID cards, for example, highsecurity door access tags that can be attacked via relay stations. Tworelay stations working together can be used to open a high security doorwhere it is controlled by an access card. If the access card isprotected by the described shield device, such attacks are powerless.

In a further described embodiment of the first scenario of FIG. 6A, theshield device 601 may be used to protect sensitive equipment. Ifsensitive equipment in an industrial control system is taking precisemeasurements and is physically vulnerable to outside emitted radio noisesignals, the described shield device may sense the levels of the noiseinside the enclosure and transmit a dampening field purely to nullifyit.

In a further embodiment of the first scenario of FIG. 6A, a hardwaresecurity module (HSM) or trusted platform module (TPM) may be sensitiveto outside attack signals at the resonant frequency of some internalpart of the silicon or construction. The shield device 601 could beseparate or built into such a device to shield internal components fromsuch an external signal targeted at modifying the behaviour of thedevice.

The shield device 601 could also be used to protect sensitive equipmentor sensors from external influence. Take for example an inertial sensorused for the detection of ground vibrations used in earthquakemonitoring. Such an inertial sensor would be sensitive to signalstransmitted to it at the sensor's natural resonant frequency. This sidechannel attack could be used to trick the sensor into seeing vibrationthat is not actually present. The shield device 601 could be configuredto be sensitive to the resonant frequency of the sensor it is protectingand if that signal is ever sent to the sensor the shield device 601 mayeffectively cancel it out protecting the ground sensor from falsevibration readings. The same could be applied to many different types ofsensors, including gyroscopes, strain sensors, MEMs microphones.

Referring to FIG. 6B, illustrated is a schematic diagram 650 showing asecond scenario of an application of a described shield device 651. Anelectronic device 652 may leak a radio frequency signal 661. The shielddevice 651 may detect the leaked signal 661 and may dampen the leakedsignal 661 by transmitting a nullifying signal 662 in the form of adampening or cancellation signal from the shield device 651. Thisresults in the leaked signal 661 being cancelled. This is effective foran electronic device 652 leaking a signal 661 within an area 655 of theshield device 651.

In a described embodiment of the second scenario of FIG. 6B, the shielddevice 651 can also be used to protect against leakage from a Faradaycage. For example, a Faraday shielded room may be used in a bank orcorporations to ensure no bugs, radios, phones, etc. work when insidethe room. The shield device 651 may be used on the outside of the roomto detect any leakage from the room and effectively scramble and nullifyit. In essence, the shield device 651 could be used to re-enforce aFaraday cage.

The shield device 651 may also be used to protect sensitivecryptographic, computation or signal processing equipment frominadvertently leaking sensitive data through side channels. Such aselectromagnetic leakage from a processor that allows an attacker withthe correct equipment to monitor electromagnet output from a processorto infer what it is doing. Side channel attacks are becoming more commonas technology for implementing such complex attacks becomes cheaper.

The present disclosure may include a system, a method, and/or computerprogram instructions causing a processor to carry out aspects of thepresent disclosure at any possible technical detail level ofintegration.

Computer readable program instructions for carrying out operations ofthe present disclosure may be assembler instructions,instruction-set-architecture (ISA) instructions, machine instructions,machine dependent instructions, microcode, firmware instructions,state-setting data, configuration data for integrated circuitry, oreither source code or object code written in any combination of one ormore programming languages, including an object oriented programminglanguage such as Smalltalk, C++, or the like, and procedural programminglanguages, such as the “C” programming language or similar programminglanguages.

In some embodiments, electronic circuitry including, for example,programmable logic circuitry, field-programmable gate arrays (FPGA), orprogrammable logic arrays (PLA) may execute the computer readableprogram instructions by utilizing state information of the computerreadable program instructions to personalize the electronic circuitry,in order to perform aspects of the present disclosure.

Aspects of the present disclosure are described herein with reference toflowchart illustrations and/or block diagrams of methods, apparatus(systems), and computer program products according to embodiments of thedisclosure. It will be understood that each block of the flowchartillustrations and/or block diagrams, and combinations of blocks in theflowchart illustrations and/or block diagrams, can be implemented bycomputer readable program instructions.

These computer readable program instructions may be provided to aprocessor of a general purpose computer, special purpose computer, orother programmable data processing apparatus to produce a machine, suchthat the instructions, which execute via the processor of the computeror other programmable data processing apparatus, create means forimplementing the functions/acts specified in the flowchart and/or blockdiagram block or blocks. These computer readable program instructionsmay also be stored in a computer readable storage medium that can directa computer, a programmable data processing apparatus, and/or otherdevices to function in a particular manner, such that the computerreadable storage medium having instructions stored therein comprises anarticle of manufacture including instructions which implement aspects ofthe function/act specified in the flowchart and/or block diagram blockor blocks.

The computer readable program instructions may also be loaded onto acomputer, other programmable data processing apparatus, or other deviceto cause a series of operational steps to be performed on the computer,other programmable apparatus or other device to produce a computerimplemented process, such that the instructions which execute on thecomputer, other programmable apparatus, or other device implement thefunctions/acts specified in the flowchart and/or block diagram block orblocks.

The flowchart and block diagrams in the figures illustrate thearchitecture, functionality, and operation of possible implementationsof systems, methods, and computer program products according to variousembodiments of the present disclosure. In this regard, each block in theflowchart or block diagrams may represent a module, segment, or portionof instructions, which comprises one or more executable instructions forimplementing the specified logical function(s). In some alternativeimplementations, the functions noted in the blocks may occur out of theorder noted in the figures. For example, two blocks shown in successionmay, in fact, be executed substantially concurrently, or the blocks maysometimes be executed in the reverse order, depending upon thefunctionality involved. It will also be noted that each block of theblock diagrams and/or flowchart illustration, and combinations of blocksin the block diagrams and/or flowchart illustration, can be implementedby special purpose hardware-based systems that perform the specifiedfunctions or acts or carry out combinations of special purpose hardwareand computer instructions.

The descriptions of the various embodiments of the present disclosurehave been presented for purposes of illustration, but are not intendedto be exhaustive or limited to the embodiments disclosed. Manymodifications and variations will be apparent to those of ordinary skillin the art without departing from the scope and spirit of the describedembodiments. The terminology used herein was chosen to best explain theprinciples of the embodiments, the practical application or technicalimprovement over technologies found in the marketplace, or to enableothers of ordinary skill in the art to understand the embodimentsdisclosed herein.

Although the present disclosure has been described in terms of specificembodiments, it is anticipated that alterations and modification thereofwill become apparent to the skilled in the art. Therefore, it isintended that the following claims be interpreted as covering all suchalterations and modifications as fall within the true spirit and scopeof the disclosure.

What is claimed is:
 1. A radio frequency radiation shield device, thedevice comprising: a receiver for detecting a near field radio frequencysignal at target frequencies; a signal processor for, responsive todetecting a signal characteristic of a detected signal meeting a triggerthreshold: sampling signal characteristics of the detected signal; anddetermining a nullifying signal that results in interference with thedetected signal to render the detected signal ineffective, thenullifying signal comprising a modulated version of the detected signal;a signaler for generating the nullifying signal; and a transmitter fortransmitting the nullifying signal at the target signals.
 2. The shielddevice as claimed in claim 1, wherein the signal processor is furtheroperable for repeating the sampling and transmitting of a determinednullifying signal at time intervals to provide the nullifying signal inresponse to a presence and form of the detected signal.
 3. The shielddevice as claimed in claim 1, wherein the signal processor is furtheroperable for determining a signal providing destructive interferencewith the detected signal to cancel or dampen the detected signal.
 4. Theshield device as claimed in claim 1, wherein the signal processor isfurther operable for determining a signal providing positiveinterference to interfere with the detected signal and render itineffective.
 5. The shield device as claimed in claim 1, wherein thesignal processor is further operable for determining a different form ofinterference for different time portions of the detected signal.
 6. Theshield device as claimed in claim 1, wherein the signal processorincludes a signal deviationer for adding a deliberate deviation ofrandom or pseudo random nature to the nullifying signal.
 7. The shielddevice as claimed in claim 1, wherein a passive mode of the signalprocessor is enabled to monitor received signals and an active mode ofthe signal processor is enabled when signal characteristics of thedetected signal meet the trigger threshold.
 8. The shield device asclaimed in claim 1, wherein the receiver and the transmitter arearranged to provide one or more axis of sufficient signal sensitivelysuitable for a current application of the shield device.
 9. The shielddevice as claimed in claim 1, wherein the receiver and the transmitterare operable for providing suitable receive and transmit gain at targetfrequencies for a current application of the shield device.
 10. Theshield device as claimed in claim 1, wherein the shield device is aportable device with a portable power supply or connectable to a powersource.
 11. The shield device as claimed in claim 1, wherein the shielddevice is provided in an integrated circuit for protecting integratedelectronic components of a device.
 12. The shield device as claimed inclaim 1, wherein the shield device is operable for protecting aprotected electronic device wherein the detected signal is an unwantedincoming signal to the protected electronic device positioned within atransmission field of the shield device.
 13. The shield device asclaimed in claim 1, wherein the shield device is operable for protectinga protected electronic device from leaking wherein the detected signalis a leaking signal from the protected electronic device positionedwithin a transmission field of the shield device.
 14. The shield deviceas claimed in claim 1, wherein the shield device is operable forprotecting remote keyless entry fobs with target frequencies in therange of 125 KHz or 134.5 KHz from relay attacks.
 15. A signalprocessing method for providing a radio frequency radiation shield, themethod comprising: detecting, by a receiver, a near field radiofrequency signal at target frequencies; responsive to detecting a signalcharacteristic of a detected signal meeting a trigger threshold,sampling signal characteristics of the detected signal; determining anullifying signal that results in interference with the detected signalto render the detected signal ineffective, the nullifying signalcomprising a modulated version of the detected signal; generating thenullifying signal; and controlling the transmitting of the nullifyingsignal using a transmitter.
 16. The method as claimed in claim 15,including repeating the sampling and transmitting of a determinednullifying signal at time intervals to provide the nullifying signal inresponse to a presence and form of the detected signal.
 17. The methodas claimed in claim 15, wherein determining a nullifying signaldetermines a signal providing destructive interference with the detectedsignal to cancel or dampen the detected signal.
 18. The method asclaimed in claim 15, wherein determining a nullifying signal determinesa signal providing positive interference to interfere with the detectedsignal and render it ineffective.
 19. The method as claimed in claim 15,wherein determining a nullifying signal determines a different form ofinterference for different time portions of the detected signal.
 20. Themethod as claimed in claim 15, including: disabling or ignoring thereceiver once a detected signal is sampled; enabling the transmitter totransmit the nullifying signal; disabling the transmitter after atransmitting interval; enabling or reading the receiver to resample thedetected signal; and repeating the process as long as a detected signalis received.
 21. The method as claimed in claim 15, including adding adeliberate deviation of random or pseudo random nature to the nullifyingsignal.
 22. The method as claimed in claim 15, including providing apassive mode of a signal processor to monitor received signals and anactive mode of the signal processor when signal characteristics of adetected signal meet the trigger threshold.
 23. A signal processingsystem for providing a radio frequency radiation shield, comprising: asignal receiver for receiving a detected near field radio frequencysignal at target frequencies; a signal sampler for, responsive todetecting a signal characteristic of a detected signal meeting thetrigger threshold, sampling signal characteristics of the detectedsignal; a signal nullifier for determining a nullifying signal thatresults in interference with the detected signal to render the detectedsignal ineffective, the nullifying signal comprising a modulated versionof the detected signal; and a signal controller for controlling thetransmitting of the nullifying signal.
 24. A radio frequency radiationshield device, the device comprising: a receiver for detecting a nearfield radio frequency signal at target frequencies; a signal processorfor, responsive to detecting a signal characteristic of a detectedsignal meeting a trigger threshold: sampling signal characteristics ofthe detected signal; and determining a nullifying signal that results indestructive interference with the detected signal to render at leastpart of the detected signal ineffective; a signal generator forgenerating the nullifying signal; and a transmitter for transmitting thenullifying signal at the target frequencies.
 25. A signal processingmethod for providing a radio frequency radiation shield, comprising:detecting a near field radio frequency signal at target frequencies;responsive to detecting a signal characteristic of a detected signalmeeting a trigger threshold, sampling signal characteristics of thedetected signal; determining a nullifying signal that results indestructive interference with the detected signal to render at leastpart of the detected signal ineffective; generating the nullifyingsignal; and controlling the transmitting of the nullifying signal usinga transmitter.